209372921 has 8 divisors (see below), whose sum is σ = 214220160. Its totient is φ = 204542128.

The previous prime is 209372909. The next prime is 209372929. The reversal of 209372921 is 129273902.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-209372921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (209372929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23795 + ... + 31383.

It is an arithmetic number, because the mean of its divisors is an integer number (26777520).

Almost surely, 2^209372921 is an apocalyptic number.

It is an amenable number.

209372921 is a deficient number, since it is larger than the sum of its proper divisors (4847239).

209372921 is an equidigital number, since it uses as much as digits as its factorization.

209372921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8223.

The product of its (nonzero) digits is 13608, while the sum is 35.

The square root of 209372921 is about 14469.7242890112. The cubic root of 209372921 is about 593.7999691131.

The spelling of 209372921 in words is "two hundred nine million, three hundred seventy-two thousand, nine hundred twenty-one".